Micrometer doctor bar assembly



Oct. 31, 1961 c. v. ALLEN 3,006,275

MICBOMETER DOCTOR BAR ASSEMBLY Filed May 13, 1960 2 Sheets-Sheet 1 I i= 2 2 7 a o 1" WWII-- INVENTOR. CLAUDE V. ALLEN ATTORNEY Oct. 31, 1961 I c. v. ALLEI'N 3,006,275

MICROMETER DOCTOR BAR ASSEMBLY Filed May 13, 1960 V 2 Sheets-Sheet 2 FIG. 2

INVENTOR. CLAUDE V. ALLEN BY/Q K:

A TTORNE Y United States Patent MICROMETER DOCTOR BAR ASSEMBLY Claude V. Allen, Richmond, Va., assignor to The Inta- Roto Machme Company, Inc., Richmond, Va., a corporatlon of Virginia Filed May 13, 1960, Ser. No. 28,969 11 Claims. (Cl. 101157) This invention relates to rotary intaglio printing presses and more particularly to an improved doctor bar assembly for such presses which enables accurate setting and resetting of the doctor bar by means of micrometer type, precisely readable adjustment screws.

Intaglio or rotogravure printing involves the use of a printing cylinder about which are normally strapped copper plates whose surfaces are etched with the design to be printed. The cylinder revolves in a trough of ink, or the ink is otherwise applied to the surfaces of the copper plates filling the etched grooves, lines or pits. A doctor bar, or blade, scrapes the cylinder surface clean leaving ink in the hollows. The design is then pressed from the inky hollows onto the paper. It is obvious, therefore, that the doctor blade mechanism must be capable of very precise setting to wipe clean the printing cylinder, must be movable away from the cylinder'to wlpe clean the ink accumulated on the blade, and must be capable of varied adjustment required to accommodate a variety of knurls, engravings, inks and adhesives.

One extremely important feature needed in wiping the rotogravure cylinder is the ability to precisely return the doctor blade to a previous setting after the blade has been thrown off the cylinder for cleaning or other reasons. On conventional doctor bar mechanisms, using worm and worm gear adjustments, resetting the blade exactly to a predetermined position after being thrown off the printing cylinder is impossible. Consequently, a great deal of time, labor and material is lost in accomplishing the frequent readjustments and resettings required.

Accordingly, it is a primary object of the present invention to provide an improved doctor blade adjustment mechanism which enables the blade to be accurately set at the position and angle with respect to the printing cylinder required to accomplish the wiping function, and which can be quickly and accurately reset to the identical previous adjustments once the blade has been thrown ed the cylinder. Another important object of the invention is to provide a doctor blade adjustment mechanism of the described characteristics in which the blade is adjustable toward and away from the printing cylinder as well as to a desired angular position with respect thereto, both such adjustments employing micrometer type screws for accurate setting or resetting of the blade.

A further object of the invention is to provide a doctor blade adjustment mechanism of the described character wherein the micrometer graduations are carried on the shafts of the adjustment screws and are quickly and easily readable in relation to an indexing collar surrounding each adjustment screw shaft.

A still further object of the invention is to provide a doctor blade adjustment mechanism of the described character wherein each adjustment screw is provided with manual means for ready setting and resetting of the doctor blade, the manual means and micrometer scale on each screw being so positioned as to enable convenient manipulation and observation by the press operator.

The novel features that are considered characteristic of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and its method of operation, to-

3,006,275 Patented Oct. 31, 1961 gether with additional objects and advantages thereof, will best be understood from the following description of a specific embodiment when read in connection with the accompanying drawings, wherein like reference characters indicate like parts throughout the several figures and in which:

FIG. 1 is a perspective view of doctor blade adjustment mechanism constructed in accordance with the invention;

FIG. 2 is an enlarged, fragmentary sectional view taken vertically through the doctor blade angular adjustment screw shaft;

FIG. 3 is an enlarged end elevational view, parts being broken away to show the construction of the horizontal adjustment screw shaft and journals;

FIG. 4 is an enlarged, fragmentary front elevation of part of the angular adjustment screw, and

FIG. 5 is an enlarged, fragmentary plan View of the horizontal adjustment hand wheel and associated parts.

Referring now more particularly to the drawings, FIGS. 1-5 illustrate a preferred embodiment of the invention wherein only a conventional rotogravure cylinder 10 of a rotary intaglio printing press is shown, together with related parts of the improved doctor blade adjustment mechanism. The mechanism comprises a support member 12 which is normally oscillated, by conventional parts not shown, to reciprocate the doctor blade 14 lengthwise of the printing cylinder 10 and thus assure a smooth wiping action.

An adjusting support plate 16 is slidably mounted on the upper surface of member 12 to move horizontally toward and away from the printing cylinder guided by rails 18 fixed to the support member 12 and which ride in grooves 20 in the end faces of the plate 16. The plate 16 is preferably hollow to conserve weight, has horizontal bottom edges and an inclined upwardly top face 22 from whose side edges extend a pair of upstanding ears 24. Journaled in openings in these ears are stub shafts 26 extending outwardly from the side ends of a swivel bar 28 to swingably support the doctor blade 14.

The doctor bar 14 is held between the pair of flat plates 30 constituting a holder which in turn is fixedly positioned in a notch 32 formed in the upper, forward edge of the swivel bar 28. A clamp plate 34 firmly holds the blade 14 and blade holder 30 secured in notch 32 by means of a plurality of screws 36.

To adjust the blade 14 at a desired wiping angle to cylinder 10, both the swivel bar 28 and adjusting plate 16 are provided with pairs of spaced rearward extensions 38 and 40, respectively, which define vertically aligned notches 42 and 44. These notches also overlie a third notch 46 in the rear edge of the oscillatable support member 12. The blade angular adjustment shaft 48, threaded in its central portion, is mounted to operate in the aligned notches 42, 44 and 46.

The upper end of shaft 48 is journaled in a block 50 which swivels on a pair of stub shafts 52 mounted in the extensions 38. Below the swivel block 50, a flange 54 on shaft 48 seats a thrust washer 56 to prevent upward movement of shaft 48. Similarly, the shaft 48 is prevented from downward movement with respect to block 50 by another thrust washer 58 and a threaded nut 60.

A threaded nut 62 swivels in the notch 44 of the adjusting plate and passes the threaded portion of shaft 48 through its central opening. The nut 62 pivots on a pair of stub shafts 64 mounted in the extensions 40 of the adjusting plate. A ratchet wrench 64 is mounted on the upper end of shaft 48 and secured thereon by a cap 66 and nut 68.

The lowermost end of shaft 48 is provided with a micrometer type scale generally indicated at 70. lhe

scale may preferably comprise a series of circles each spaced apart a distance equal to the pitch of the threaded portion of shaft 48. These lines are preferably etched and each is numbered in sequence from bottom to top as best illustrated in FIG. 2. A series of spaced parallel lines, preferably crossing the circles perpendicularly, is also etched into the shaft so as to divide the circumference of the shaft into equal increments. These lines are also numbered as indicated in FIGS. 2 and 4. A sleeve or collar 72 is attached to the underside of nut 62 and surrounds the scale portion 70 of the adjustment shaft. An index mark 73, FIG. 4, is positioned on the lower edge of the collar.

For adjusting the plate 16 toward and away from the printing cylinder 10, there is provided another pair of shafts 74, one near each end of the plate 16; The threaded central portions of these shafts pass through threaded openings in the fixed journal blocks 76 fastened to the rear surface of member 12 by screws 78. The forward ends of shafts 74 are fastened to the plate 16 in such manner as to permit turning of the shafts. A preferred method of doing this is best illustrated in FIG. 3.

A ball bearing raceway 78 is held in a notch 80 in plate 16 Whose rear opening is closed by a thrust plate 82. The bearing raceway 78 journals the forward end of shaft 74 being seated between the shaft shoulder 84 and a thrust washer 86 secured to the end of the shaft. The rear end of each shaft 74 has a hand wheel 88 for manual turning. Between the hand wheel and the fixed bearing 76, each shaft 74 is provided with a micrometer type scale portion 90 which is similar to the described portion 70 of shaft 48. Collars 92 having index marks 94 on their rear edges surround the scale portions 90 of shafts 74 and are secured to the fixed bearings 76.

To operate the improved doctor blade assembly described above, the press operator grasps the pair of wheels 88 and turns them to move adjustment plate toward or away from cylinder 10, as necessary. Turning of the threaded shafts 74 in the threaded bearings which are fixed causes the plate 16 to move in the desired direction. The proper angular setting of blade 14 with respect to the cylinder is then accomplished by the operator by turning the ratchet wrench 64 either clockwise orcounterclockwise. Since shaft 48 merely rotates in the block 50 but moves axially in the nut 62 and these parts are respectively pivoted to the swivel bar 28 and plate 16, the angular relation of the bar and plate will change causing blade 14 to contact the printing cylinder at the appropriate angle. When the described adjustments have been made to suitably wipe the ink from the cylinder, the operator may quickly return the blade to the same exact setting as often as necessary during the printing run or during a subsequent printing. To duplicate the setting, the operator notes, or records, the micrometer recording on the shafts 74 and 48 and returns the shafts to their identical readings.

As will be apparent from the preceding descriptions of the shaft scale portions 70 and 90, the circles represent pitch distance or complete turns of the shaft which may be sighted against the indexed edges of the sleeves 72 and 92. The straight lines on each shaft divide the shaft circumference in equal segments and so when sighted against the index marks 73 and 94 reveal the exact fraction of a turn made by the shaft in addition to the complete turns. In other words, if indexes 73 and 94 are initially properly aligned with circle number one and line number 1, any subsequent turning of the shaft can be read exactly to the complete number of and fractional parts of a turn by sighting the last exposed circle and the crossing line aligned with the index.

Use of the described mechanism to quickly return to a precise, proper setting enables the blade 14 to be cleaned often, or rest at a subsequent time, without undue loss of time and materials. If necessary to accommodate different printing cylinder sizes, micrometer adjustment 4 shafts similar to 74 may be utilized to raise and lower the oscillating support member 12.

Although a certain specificembodiment of the invention has been shown and described, it is obvious that many modifications thereof are possible. The invention, therefore, is not to be restricted except insofar as is necessitated by the prior art and by the spirit of the appended claims.

What is claimed is:

1. In a rotary intaglio printing press, the combination of a printing cylinder, a doctor blade for wiping the cylinder mounted in a swivel bar, a support plate for said blade and swivel bar movable toward and away from said cylinder, pivot means between said support plate and swivel bar for permitting changing of the angle of the doctor blade with respect to the cylinder, and micrometer adjusting means for said support plate and swivel bar for accurately setting and resetting the position and angle of the doctor blade relative to the cylinder.

2. In a rotary intaglio printing press, the combination according to claim 1 wherein said micrometer adjusting means comprises at least one threaded shaft having indicia of the total and fractional number of turns of the shaft taken from a fixed starting point in setting the said doctor blade.

3. In a rotary intaglio printing press, the combination according to claim 1 wherein said micrometer adjusting means comprises a bearing block pivoted to said swivel bar, a nut pivoted to said support plate, a shaft journaled in the bearing block and threaded through the nut, and indicia on said shaft for indicating total and fractional number of turns of the shaft from a fixed starting point, whereby to exactly indicate the angular setting of said doctor blade.

4. In a rotary intaglio printing press, the combination according to claim 3 wherein said indicia on the shaft comprises spaced parallel circles etched on the periphery of the shaft and aset of spaced, parallel lines perpendicular to said circles.

5. In a rotary intaglio printing press, the combination according to claim 4 wherein is additionally provided a sleeve secured at one edge to said nut and surrounding said shaft, said sleeve having an index at its other edge, whereby the setting of the doctor blade may be exactly read by the relative alignment of said other sleeve edge with the circles on the threaded shaft and the relative alignment of the index with the perpendicular lines on the shaft.

6. In a rotary intaglio printing press, the combination according to claim 3 wherein said threaded shaft is provided with a ratchet wrench for incremental turning of the shaft to adjust the angle of the doctor blade.

7. In a rotary intaglio printing press, the combination according to claim 1 wherein is additionally provided a support member including a guide rail, said support plate being movably carried by the support member for adjustment toward the cylinder guided by said rail.

8. In a rotary intaglio printing press, the combination according to claim 7 wherein said support member is oscillatable to reciprocate the doctor blade lengthwise of the printing cylinder.

9. In a rotary intaglio printing press, the combination according to claim 7 wherein said micrometer adjusting means comprises a block fixed to said support member and having a threaded opening, a shaft passing through said fixed block and threadedly engaging the opening, one end of said shaft being rotatably secured to said support plate, and graduations on said shaft to indicate the complete and fractional number of turns of the shaft from a fixed starting point, whereby to exactly indicate the position of the doctor blade for a given setting toward or away from the printing cylinder.

10. In a rotary intaglio printing press, the combination according to claim 9 wherein said shaft is provided with a hand wheel for turning the shaft and a collar is secured at one edge to the fixed block and surrounds the shaft, said collar having an index at its other edge, whereby the relative setting of the doctor blade toward or away mm the printing cylinder may be exactly read by the relative alignment of the index edge of the collar with the graduations on the shaft.

11. In a printing press, the combination of a printing cylinder, doctor blade means including a blade engageable with the cylinder to wipe the cylinder preparatory to printing, support means movably supporting said doctor blade means for adjustment relative to said cylinder, micrometer adjusting means connected between said support means and said doctor blade means for accurately setting and resetting the position of the doctor blade means and its blade with respect to the cylinder, said micrometer adjusting means including a screw connected to one said means and a nut connected to the other said means, said screw having a shank including a threaded portion cooperative with said nut and a scale portion bearing graduations to exactly indicate the number of complete and fractional turns from a fixed point taken by the screw for a given setting of the doctor blade, said scale portion comprising a plurality of circular lines equally spaced axially of said shank and equally spaced parallel lines extending axially of said shank and cross ing said circular lines, said nut having a sleeve portion extending beyond the threaded portion of said shank for cooperation with said scale portion, said sleeve portion having an accurately disposed free end edge for cooperation with said circular lines, and an index mark at said edge for cooperation with said axial lines.

References Cited in the file of this patent UNITED STATES PATENTS 1,315,318 Maddison Sept. 9, 1919 2,695,588 Steinbrecker Nov. 30, 1954 FOREIGN PATENTS 855,679 France May 17, 1940 

